How, why, and where does moss grow?
Dry land limits the spread of moss plants since all parts must be constantly moist. Moss is a mat forming carpet that relies on every part being in contact with a water source. That is the environment controls the mosses’ state of hydration they cannot control it internally. This limits how thick the mosses can grow as well as how tall. Today mosses dominate in cold, wet climates so are common in the circumpolar tundra. The common cushion moss, Grimmia laevigata, grows on bare rock in a broad range of environments on every continent except Antarctica because it is tolerant of prolonged nearly complete desiccation. Mosses are sexually reproductive with an alternation of 1n-2n generations in their life cycle. Despite the dominant life phase being haploid (the gametophyte generation) they retain a genetic diversity as great as any vascular plant that is diploid in its dominant life phase (the sporophyte generation). Not all creatures have to be diploid their entire lives. One set of chrom
